Spectrum of CT findings of acquired adult non-neuromyopathic ocular dysmotility inflicted by traumatic and non-traumatic afflictions of extra-ocular muscles

Abstract

<title>Abstract</title> <bold>Background:</bold> Acquired adult ocular dysmotility are relatively common caused by variety of traumatic and non-traumatic disorders affecting the extra-ocular muscles (EOMs). Computed tomography (CT) is a quick and widely available imaging modality that provides a key role in evaluating these conditions by delineating muscle morphology and excellent bone and soft-tissue visualization. <bold>Aim of the study:</bold> to characterize and categorize the spectrum of CT findings in some acquired adult non-neuromyopathic ocular dysmotility caused by both traumatic and non-traumatic extra-ocular muscle afflictions, providing a practical imaging framework for radiologists and referring clinicians. <bold>Methods</bold> 40 adult patients were included in this retrospective study (with a mean age of ~30 years (range 16–50).; 70% male) presenting with acquired traumatic and non-traumatic ocular dysmotility with exclusion of congenital, neuromyopathic, or neurogenic causes. All underwent non-contrast orbital CT. Demographic data, clinical features, affected muscles, laterality, and CT findings—including fracture lines, muscle morphology, and associated orbital or sinus abnormalities—were analyzed. <bold>Results</bold> Traumatic etiologies slightly predominated (52.5%) over non-traumatic causes (47.5%) with blunt orbital trauma was the most common cause (52.5%). While myopia-related disorders (22.5%) and isolated idiopathic cases (20%) comprised the majority of non-traumatic etiologies. The inferior rectus and superior oblique muscles were the most frequently affected EOMs (27.5 % each), followed by the medial rectus (22.5 %). CT findings demonstrated thinning or atrophy (50 %), with detachment/disinsertion in (22.5 %) Orbital wall fractures were identified in 22.5% and sinusitis in 27.5% of cases with optic nerve was intact in all patients. In non-traumatic cases, thyroid ophthalmopathy manifested as muscle hypertrophy, while high-myopia–related strabismus fixus manifested as muscle elongation and displacement. <bold>Conclusion</bold> CT provides a non-invasive, available, rapid, and comprehensive tool for evaluating both traumatic and non-traumatic causes of acquired ocular dysmotility in adults. It effectively characterizes the pattern and extent of ocular dysmotility, guiding diagnosis, and surgical planning and follow up.